In the debate about the origins of Standard English, the role of the written medium of administration has been the centre of attention. An administration cannot function without the activities of its traders, who by virtue of their daily goings-on engage in two-way, face-to-face interaction with speakers of other dialects. This chapter explores the written language of London merchants as it was prior to the development of Standard English, looking at the fusion of Anglo-Norman and Middle English as well as the morphological changes that came to form Standard English, and also factoring in patterns of trade contact. The conclusion is that Standard English may be regarded as a side-effect of change in commerce.